Ways to diagnose rings as source of oil consumption

General engine tech -- Drag Racing to Circle Track

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Newold1
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Re: Ways to diagnose rings as source of oil consumption

Post by Newold1 » Wed Jan 03, 2018 7:58 pm

We really should have some more info here to start to help you find your problem possibly.

First, I would comment that the pic to the piston crown also appears to show a little of the cylinder wall finish and I am seeing quite a few vertical scratch lines in the bore finish if that is what they ultimately turn out to be that will allow a fair amount of oil, especially synthetic to pass the rings and still show fairly decent compression and leak downs. The cleaned off outer tops of pistons definitely indicate a moderate amount of oil is going past the rings. Your plugs have shown the sooty condition that shows some oil is burning on them but definitely not enough to foul. What heat range plug are these?


However we should gather some more info and facts before trying to help nail down this problem.
First you mentioned your shop bored and honed and gapped the rings and you assembled? Is that correct?
Which set and type of rings that were used is important to know as well as your bore to piston clearances. What were those and how were the bores measured and piston to bore clearance determined?
What finish RA was used in final honing and were the cylinders plateau honed as a final step?
What assembly lubes and fluids were used during initial assembly?
Is there a possibility the second ring was installed upside down?
What is the width of the rings used and were they a standard tension set, especially the oil rings.
What kind of initial break-in driving procedure and time and distances and speeds were used if any?
What oil pressures is the engine showing from idle up thru you top rpms experienced?
Have you looked with the bore scope down the intake manifold to see if any oil in entering from the bottom of the intake to head gaskets location and oiling the intake track?
What weight and brand of both the synthetic and conventional oils?
What thermostat temp are you using in the cooling system and what temperature does the engine operate at when being cruised or daily driven?
What is your camshaft type and specs?
What cylinder heads and what was done to them for use on the engine, new valves? new guides and types, head gaskets?

Sorry, I know this seems like a lot of questions but I always generally find the "DEVIL" is in the details !! and guesses are only 50% accurate at best !
The Older I Get, The Dumber I Get :wink:

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Re: Ways to diagnose rings as source of oil consumption

Post by zwede » Wed Jan 03, 2018 10:13 pm

Thanks for taking the time to help. I found the paperwork for the machine work. It was done November 2006. Man, time flies, I really didn't think it was that long ago!
Newold1 wrote:
Wed Jan 03, 2018 7:58 pm
What heat range plug are these?
They're fairly hot plugs as all my driving is short distance, 10-15 miles. NGK heat range is 4. Champion 14.
First you mentioned your shop bored and honed and gapped the rings and you assembled? Is that correct?
Correct.
Which set and type of rings that were used is important to know as well as your bore to piston clearances. What were those and how were the bores measured and piston to bore clearance determined?
Rings are "SP R9590 45". Looking at summit racing that's a sealed power file-fit plasma-moly. But I can only find the R9590 35 on summit? Anyone have the full specs for the R9590 45?

Sorry, I don't remember the piston-to-wall clearance although he told me. I'm pretty sure he put it a bit on the loose side of the spec Probe gave us. That said, there is no noise at a cold start so the clearance can't be that great.
What finish RA was used in final honing and were the cylinders plateau honed as a final step?
Don't know the RA, but yes it was plateau honed.
What assembly lubes and fluids were used during initial assembly?
I can't recall anything much special was used at all. It's a roller cam so no cam gunk, just motor oil.
Is there a possibility the second ring was installed upside down?
Certainly. :) I have no illusions of being perfect. This was only the second engine I've assembled though so I did take my time and double checked everything.
What is the width of the rings used and were they a standard tension set, especially the oil rings.
Hopefully someone has the specs for the sealed power R9590 45.
What kind of initial break-in driving procedure and time and distances and speeds were used if any?
Just driving around varying rpm and no WOT for a few hundred miles.
What oil pressures is the engine showing from idle up thru you top rpms experienced?
Oil pressure is great. 40 PSI hot idle, 70 PSI 1,500 rpm and up.
Have you looked with the bore scope down the intake manifold to see if any oil in entering from the bottom of the intake to head gaskets location and oiling the intake track?
Well, here's the next can of worms. :) The intake used to be very oily with drops hanging off the underside of the butterflies and puddles on the valves. After I switched to conventional oil this has pretty much completely cleared up. Just a thin oil film in the runners before the injectors (after injectors is clean due to fuel wash).
What weight and brand of both the synthetic and conventional oils?
Mobil1 10W-30 and also oW-40.
Conventional was Delvac 15W-40 for 1,500 miles and now Rotella 15W-40 for 400 miles.
What thermostat temp are you using in the cooling system and what temperature does the engine operate at when being cruised or daily driven?
180F and it runs 180. In the summer if I'm idling with AC on it will creep up to 205F where my fans turn on full speed instead of half and it drops back. I think I have the only C3 'vette with a big block that doesn't run hot!
What is your camshaft type and specs?
Lunati H-Roller. 231/239. 600 lift. 110 LSA. PN 60212.
What cylinder heads and what was done to them for use on the engine, new valves? new guides and types, head gaskets?
Edelbrock aluminums, their "rovals". They have been refreshed just before the shortblock. New valves, guides. Head gaskets are Fel-Pro.
Sorry, I know this seems like a lot of questions but I always generally find the "DEVIL" is in the details !! and guesses are only 50% accurate at best !
Well, I've been messing with it since 2006 so a few minutes digging up info for you is nothing! :)

I also found the receipt for the pistons, they are "Probe Forged PRO-P2465F-040".

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Re: Ways to diagnose rings as source of oil consumption

Post by user-23911 » Wed Jan 03, 2018 10:30 pm

zwede wrote:
Wed Jan 03, 2018 3:39 pm


If it was that rich I'd think the oil level would go up?
Not noticably.

statsystems wrote:
Wed Jan 03, 2018 3:47 pm
The upper plugs are rich at cruise. The lower plugs are better but still rich.
They're fouled from oil, possibly rich too but mainly oil, as seen on the threads which are wet......with oil not fuel
zwede wrote:
Wed Jan 03, 2018 5:03 pm

Broken in on synthetic, which could well the the root of all this. I now know better.

I've never used synthetic, don't see the point.
Use cheap oil, drive it like you stole it.

zwede wrote:
Wed Jan 03, 2018 5:05 pm


No signs of oil in the exhaust, just dry soot.
The plugs are covered....as above
hoodeng wrote:
Wed Jan 03, 2018 6:17 pm
Your picture of the piston is showing oil wash around the o/d , when oil passes the ring set it dissolves the crown residue closest the bore leaving a distinctive bare/clean crown band. If contamination is coming past the guides the piston crown will have an even residue deposit.
The fuel from the injector washes the oil deposits from the top of the piston. There shouldn't be any deposits there to start with.


Showing pictures of only half the plugs is only half a job done.
Waiting for the others?

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Re: Ways to diagnose rings as source of oil consumption

Post by zwede » Wed Jan 03, 2018 10:55 pm

joe 90 wrote:
Wed Jan 03, 2018 10:30 pm
Showing pictures of only half the plugs is only half a job done.
Waiting for the others?
Didn't think they would add much as they're pretty much the same. But here are 2-4-6-8:
2468.jpg
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Re: Ways to diagnose rings as source of oil consumption

Post by zwede » Wed Jan 03, 2018 11:02 pm

Exhaust tip doesn't look oily.
Photo Jan 03, 21 58 18.jpg
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user-23911

Re: Ways to diagnose rings as source of oil consumption

Post by user-23911 » Wed Jan 03, 2018 11:53 pm

Those second 4 plugs, they look too lean to me.
The one on the left looks a bit oily too.

hoodeng
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Re: Ways to diagnose rings as source of oil consumption

Post by hoodeng » Wed Jan 03, 2018 11:54 pm

Just out of curiosity , how much time passed between the block being machined and parts being installed ? The reason i ask is that there are some corrosion inhibitor coatings used in bores that are nearly impossible to clean out if left for a considerable period of time .
You can wash till the cows come home, the bore looks clean but the crosshatch can remain loaded, when you re hone the bore and set the cut the head runs unloaded for a couple of turns till it cuts a new surface, you can hear the hone change.

Cheers.

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Re: Ways to diagnose rings as source of oil consumption

Post by statsystems » Thu Jan 04, 2018 12:44 am

That's why I don't use black shelled plugs. You can't see how much heat is in the shell.

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Re: Ways to diagnose rings as source of oil consumption

Post by zwede » Thu Jan 04, 2018 9:03 am

hoodeng wrote:
Wed Jan 03, 2018 11:54 pm
Just out of curiosity , how much time passed between the block being machined and parts being installed ?
Maybe a week.

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Re: Ways to diagnose rings as source of oil consumption

Post by zwede » Thu Jan 04, 2018 9:20 am

statsystems wrote:
Thu Jan 04, 2018 12:44 am
That's why I don't use black shelled plugs. You can't see how much heat is in the shell.
I pulled the 1-3-5-7 plugs last night. These are NGKs so they have the cad plated shell. Difference compared to previous plugs is on these I set target AFR to 14.7 for idle and cruise. Previously it was 14.0 idle, 14.2 cruise. And just so we're all on the same page: This is just driving around the neighborhood, speed up to maybe 50mph. A couple romps here and there. All trips were short distance, 10-15 miles so lots of cold starts.
1357.jpg
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Re: Ways to diagnose rings as source of oil consumption

Post by Belgian1979 » Thu Jan 04, 2018 9:33 am

MadBill wrote:
Wed Jan 03, 2018 6:47 pm
Per Belgian's suggestion, a simple way to check crankcase pressure in a wet sump engine is to hook up a vacuum gauge to the dipstick tube. For an SB/BB Chev with deleted mechanical fuel pump, drilling and tapping the blank off plate is a simple approach. Also for most SBCs, there is a bolt hole in the front face passenger side of the block that is drilled through. (the one you can use to hold the pushrod in place during pump install). Likewise any other bolt-on access cover or if all else fails, many intake manifolds seal the valley area and can accept a vacuum fitting.
Haven't thought about these. Thanks Bill, going to try this myself.

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Re: Ways to diagnose rings as source of oil consumption

Post by Belgian1979 » Thu Jan 04, 2018 9:57 am

zwede wrote:
Wed Jan 03, 2018 10:13 pm
Have you looked with the bore scope down the intake manifold to see if any oil in entering from the bottom of the intake to head gaskets location and oiling the intake track?
Well, here's the next can of worms. :) The intake used to be very oily with drops hanging off the underside of the butterflies and puddles on the valves. After I switched to conventional oil this has pretty much completely cleared up. Just a thin oil film in the runners before the injectors (after injectors is clean due to fuel wash).
This I find odd. If you would have an intake gasket failing, then it would suck oil no matter if you would be using synthetic or regular oil. Aside this, the second question would be how you could get oil on the butterflies. I had oil on the intake tract, but it was after the injector. So in my case there were any 3 reasons possible, either it sucked in oil from the rocker stud holes, from the valves, from the holes that I have in my itb runners to provide for vacuum to the vacuum chamber. I never had oil on my butterflies though.
What is above the butterflies that would allow oil in ? The PCV ?

One test I did to establish gasket failure or intake rocker studs leaking was mount a tiny wool hair to a piece of long metal rod and poke that into the runner while at the same time putting the crankcase under pressure. I never saw it move which it should have if there had been a leak. I thus ended up with 2 things remaining, pcv leaking oil into my vacuum chamber and/or valve guide clearance.

How much vacuum does it create when decelerating ?

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Re: Ways to diagnose rings as source of oil consumption

Post by zwede » Thu Jan 04, 2018 10:09 am

Belgian1979 wrote:
Thu Jan 04, 2018 9:57 am
Aside this, the second question would be how you could get oil on the butterflies.
My thinking is that during overlap air/oil mix comes out of the cylinders back into the intake. So an oily intake does not necessarily mean the oil is introduced via the intake. At least that was my conclusion after I replaced the intake gaskets multiple times, sealed the rocker studs and put a catch can on the PCV and the intake looked just as oily as before.

Here's what I saw on the valves when switching oils
Valves.jpg
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Re: Ways to diagnose rings as source of oil consumption

Post by Belgian1979 » Thu Jan 04, 2018 10:25 am

Zwede, where is your PCV located and what style intake/throttle body do you use ?
If reversion would cause oil to be blown back so that you find the butterflies covered it would also be covered in soot from the exhaust.

Also, the valves like that could indicate valve guide issues. This is one of the suspects in mine which does the same thing. It does however mainly smoke on decel. However decel is a situation where the PCV might also let in oil.
The fact that the synthetic puddles on the valve, might be due to it being more fluid at normal temps (OW40). This is an argument for the valves.
My valves have some wiggle to them when testing. I was pointed out that this is not a sure fire way to diagnose valve guide clearance issues.
My heads were brand new and I assumed that the guide job was good out of the box. This will probably have been the only thing I have not measured/checked upon building and it might be just this that is biting me in the ass.

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Re: Ways to diagnose rings as source of oil consumption

Post by Newold1 » Thu Jan 04, 2018 10:57 am

Thank you for taking the time to answer as best you could all those questions. The new pics and description of the intake track is a major confirmation that a major amount of oil is entering the combustion and intake spaces of the engine.
Since you have been using your bore scope could you also get a couple of pics of the actual cylinder walls on a couple of cylinders? If you have some major ring problem I think these pics will lead to that problem if it exists.

Couple more questions:
1. I am guessing at this point that this is a standard 454 engine block and standard 454 stroke with a +.040 overbore? Kind of an odd overbore, why?
2. Where the heads resurface cut anything more than .003" to .005" or more?
3. Was the block decked any significant amount ?
4. Do you know what the rod and main clearances were set at?
5. Was there any change in stroke?, Rod length?
6. With the engine running have you pulled the PCV hose and PCV and looked for how much pressure is coming from the crankcase. Simple quick check done at idle and maybe 2500 rpms?
7. Why such heavy oils on what at this point seems to be a pretty mild street engine?

These questions get easy to answer with a build sheet. Every major rebuild or build of a performance engine should produce a BUILD SHEET, whether the shop or the owner puts it together as best they can!

Somewhere among these conditions and questions is an answer to your issue and I just hope the solution is fairly easy and does not require a new rebuild or major rework.
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